1. Field of the Invention
An object of the present invention is a method for addressing a mobile telephone. The field of the invention is that of mobile telephony considered in combination with the Internet. It is an aim of the invention to enable the making of incoming calls, in data (DATA) mode, for GPRS and UMTS type mobile terminals. Another aim of the invention is to limit the possibilities of possible destructive attacks against mobile terminals visible from the public Internet. Yet another aim is to enable the user to check those applications and entities external to the network that may contact him or link up with him in data mode. Another aim again is to enable a link-up with a user not just on one terminal alone but also on a known list of terminals belonging to him.
2. Description of the Prior Art
In the prior art, in order to link up with a mobile telephone through the Internet, it should be possible to identify it by a comprehensive identifier known from the public Internet. The mobile terminal should also be known on the Internet, namely it should have an allocated public Internet address.
Current solutions simply use permanent public Internet addresses for the mobile terminals, i.e. permanently allocated addresses at the public Internet level, depending in practice on a fast deployment of version 6 of the Internet Protocol (IPV6). Indeed, the number of public addresses available in version 4 of the Internet protocol (IPV4) is increasingly limited. These addresses are allocated by three international offices known as RIR or “Regional Internet Registries”. However, in practice, there remain few IPV4 addresses. Certainly, the number of them that remains is insufficient in comparison with the number of mobile telephones that will be connected in GPRS or UMTS mode.
It must be noted however that the deployment of IPV6 in the GPRS/UMTS structure will entail a major cost. The availability of this protocol is furthermore uncertain, especially in the terminals. Finally IPV6 provides only a low-level routing address solution. The problem of the symbolic identification of the user, and not of his terminals, and the problem of securing incoming connection requests, namely the problem of determining who can contact which terminal, still has to be resolved. There also remains the problem of the flexibility of the management of this securing process, namely whether the user can control third-party access to his terminals.
Despite the limits of IPV4, the number of users connected to the Internet has increased by means of network address translation (NAT) techniques. An Internet service provider (ISP) or a company may manage a set of private addresses in its own network, these addresses being allocated in any unspecified way to the active terminals of the network, since they are not visible from the public Internet. These private addresses are put into correspondence dynamically, by the NAT equipment, with a public address. Since only one set of public addresses, corresponding to the maximum number of terminals, can be active at one and the same time, it is then managed by the service provider or company.
The problem with this solution is that it is quite impossible to initialize a session, directed to a terminal on the private network, from the public Internet, since the public address that has been allocated to it is neither known nor (above all) published.
A possible solution to this problem of addressing, which is beginning to be deployed in fixed data networks, is to set up dynamic Domain Name Servers (DNS) to publish the association between a machine name in FQDN (Full Qualified Domain Name) form and its IP address, which may be possibly dynamic. This approach enables an “incoming” addressing of the terminal. Other approaches are more application-specific. These are, for example, instant messaging applications, in which a “customer” software program registers the terminals, and therefore the external public address that it has been dynamically allocated, with a server external to the private network.
These approaches have a certain number of drawbacks. In particular, they do not take account of the specific characteristics of the GPRS and UMTS mobile data networks.
Thus, the GPRS standard specifies that the terminal can be addressed in the “incoming” direction by the GGSN (Gateway GPRS Support Node), but this function will not be necessarily carried out in the first deployed versions of these devices. Indeed, unlike the terminals of the fixed networks, the mobile telephone may be available for given sessions without having any address allocated in the GPRS network. In this case, it is the GGSN that will contact the terminal and allocate the address, in a more general context, including QoS (Quality of Service) parameters, called the PDP (Packet Description Protocol) context, the PDP being any packet network protocol for which GPRS offers compatibility. It must be noted that this address allocation policy corresponds in practice to a choice of the operator with a dependence on the mechanisms implemented by the equipment suppliers.
The current solutions also have drawbacks such as:
in the case of IPV4 addresses, an inability to cover the requirements of the large-scale consumer market, it being known that there are not enough addresses available for the totality of the mobile terminals in use,
in the case of IPV6 addresses, these solutions entail a full change in infrastructure, with practical deployment in a relatively distant future. It must also be noted that these two approaches provide for direct visibility of the terminals from the public Internet. A clear danger is that Denial of Service or DoS type attacks, namely cases of denial of service that could make the target terminals inoperative,
dynamic DNS type solutions cover only a part of the needs of the mobile data networks: indeed, it is a fundamental assumption that it is a client software program at the terminals that registers itself with the external dynamic DNS server. If the terminal can be linked up with, but has no Internet address at the given point in time (this is so in the case of the management of dynamic addressing by GPRS), then it is not known to the DNS server even if it is possible, potentially, to link up with it, typically through its telephone number (MSISDN). What is needed therefore is a generic notification mechanism both at the public Internet and, potentially between the GGSN gateway and the terminal. It is needed at the public Internet to report that the terminals belonging to Mr. Dupont or having a number 336xxxxxxxx, must be contacted to open an interactive game session on the port P, and it is needed potentially between the GGSN gateway and the terminal, if this terminal is not capable in practice of initializing an incoming data connection to the terminal.